As shown in FIG. 1, the conventional scanner 1a generally uses a motor (not shown) as a power source, and a change gear set 10a and a flexible member 11a, such as a belt or a steel rope, to displace a charge coupled device (CCD) 12a such that the CCD 12a is moved along the scanning direction.
However, the change gear of the conventional scanner can only provide a constant speed ratio to the scanner when being driven by the motor. Therefore, the resolution of the scanner cannot be adjusted.
It is the object of the invention provide a gear assembly with variable speed ratios for a scanner wherein two gear sets with different speed ratios are arranged on a rotary disk and the rotary disk is driven to select the desired speed ratio, such that the scanner is able to perform the scanning task at different resolutions.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawings, in which: